What is cancer fatigue?

Fatigue means feeling very tired, exhausted and lacking energy. It can be a symptom of the cancer itself or a side effect of treatment.

Fatigue is very common in people with cancer. Research suggests cancer related fatigue affects almost 65 out of 100 people with cancer (almost 65%).

For many, it can be the most troubling symptom of treatment and the most disruptive side effect of all.

Cancer related fatigue can affect you physically, emotionally, and mentally. How long it lasts, how severe it is, and how often you might have it is different from person to person.

Symptoms of fatigue

Cancer related fatigue symptoms are very general and other things can cause them too.

Tell your doctor or nurse about any new or unusual symptoms you might have. They can help try to work out the cause and how to manage them.

Here is a list of some symptoms you might have if you have cancer related fatigue:

  • lack of energy – you may just want to stay in bed all day
  • the need to rest even when you’ve done little or no activity
  • feeling you just cannot be bothered to do much
  • sleeping problems such as unable to sleep or disturbed sleep
  • finding it hard to get up in the morning
  • feeling anxious, sad or depressed
  • pain in your muscles – you may find it hard to climb stairs or walk short distances
  • feeling breathless after doing small tasks, for example, having a shower or making your bed
  • finding it hard to concentrate, even just watching TV or talking to a friend
  • finding it hard to think clearly or make decisions easily
  • loss of interest in sex
  • loss of interest in doing things you usually enjoy
  • negative feelings about yourself and others

How long can fatigue last?

Cancer related fatigue can be severe and last for different amounts of time depending on what’s causing it. Fatigue is different from tiredness which is usually short term and you feel better after you stop, sleep or rest. Cancer fatigue doesn’t usually go away with sleep or rest.

The symptoms of fatigue can often improve after your cancer treatment finishes. But fatigue can continue for several weeks, months, or even years after treatment.

How fatigue can affect your daily life

Fatigue can be very frustrating. You and your relatives might underestimate how much it can affect daily life.

Everyday life can be difficult and you might not have the energy to cook, clean, bathe or go shopping. You might not even feel up to a chat. Things that you used to find easy to do can feel like hard work.

Fatigue can affect the way you feel about yourself and your relationships with other people. You can feel very down and not want to go out or be with people which can be hard for them to understand.

You might have to stop working or cut down your hours. 

Some people feel like fatigue is a constant reminder of their cancer and this can be hard to accept.

You might worry that because you feel so tired all the time your cancer could be getting worse. But it is more likely to be a side effect of treatment, or due to the fact that cancer can cause fatigue.

At the start of, and during your treatment your nurse or doctor will ask about your symptoms and how they affect your daily life. It’s important to tell them how you’re coping day to day and if you are struggling.

Managing cancer fatigue

Fatigue is very real and can have a big impact on your life. There are some things you can do to help with fatigue. Speak with your doctor or nurse if you are feeling very tired or if you think you have symptoms of fatigue. There are ways of managing it and your healthcare team will try to help you.

  • International Psychometric Validation of an EORTC Quality of Life Module Measuring Cancer Related Fatigue (EORTC QLQ-FA12)
    J Weis and others
    Journal of the National Cancer Institute, 2017. Volume 109, Issue 5

  • A New Approach to Understanding Cancer-Related Fatigue: Leveraging the 3P Model to Facilitate Risk Prediction and Clinical Care

    Alix G. Sleight and others

    Cancers, 2022. Volume 14, Issue 8.

  • Tiredness / fatigue in adults
    National Institute for Health and Care Excellence (NICE), 2015. Last updated October 2021

  • Cancer-related fatigue: ESMO Clinical Practice Guidelines for diagnosis and treatment

    A. Fabi and others

    Annals of Oncology, 2020

  • Cancer-related fatigue treatment: An overview
    H Mohandas and others
    Journal of Cancer Research and Therapeutics, 2017. Volume 13. Issue 6, Pages 916 - 929

  • The information on this page is based on literature searches and specialist checking. We used many references and there are too many to list here. Please contact patientinformation@cancer.org.uk with details of the particular issue you are interested in if you need additional references for this information.

Last reviewed: 
14 Aug 2023
Next review due: 
14 Aug 2026

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